The disclosure relates to fuel filter assemblies and in particular to fuel filter assemblies that include a motor driven pump to move fuel through the filter assembly.
Fuel filter assemblies are configured to condition fuel prior to delivery to systems that consume the fuel, such as internal combustion engines. Fuel filter assemblies define a housing that routes fuel through one or more filter media configured to remove particulates and separate water from the fuel. The filter assembly may include a motor-driven pump that moves fuel through the assembly. The motor for driving the pump may be a brushed or brushless motor. Brushless motors are referred to as BLDC motors and require a drive circuit to generate the rotating magnetic field that drives the motor. Power consumed by a BLDC motor will be proportional to the torque needed to rotate the pump to which the motor is connected.
The filter media in a filter assembly must be periodically replaced to maintain the removal of particulates and water. Filter media may be contained within a disposable housing, which may be referred to as a filter cartridge, or may be supported on a filter element that is placed into a re-usable housing that may be opened for this purpose. When the filter media is replaced, and the filter assembly housing is closed, a large volume of air remains in the housing and must be displaced by fuel prior to resuming normal system operation. The process of displacing fuel with air is called “priming” the filter assembly. Various manual pumps have been proposed for this purpose. It has also been proposed to provide a separate pump which rotates in a first direction to empty the filter housing and operates in a reverse direction to prime the filter housing after a service event. These prior art approaches complicate the filter assembly by requiring additional components, connections and hardware.
There is a need in the art for a self-priming fuel filter assembly that does not require additional components.